Not sure, that's why I'm asking anyone for info. We use solid rubber (fuel) and liquid nitrous (oxidizer) for the hybrids and I was wondering if it would be possible to use a solid oxidizer (KNO3 ?) and a liquid fuel (alcohol, kerosene, ???) to allow multiple starts and stops. Just thinking about some ideas..

If KNO3 were soluble in alcohol or gasoline. Humm? Then it would be a liquid with only one tank. That's too simple though it would have already been done right? What about alcohol dissolved in NO2? Or something like that? I wonder if super saturated KNO3 in solution with sugar or some other fuel could be made to burn? Thanks for the topic I'll get my chemistry book out and figure some things out. Let you know If I find out anything interesting. If any oxidizer is soluble in the fuel it may work that way.

Monroe

I bet something is soluble in NO2 I don't think many think about NO2 as a liquid there may be a process that could make a bi propellant liquid from the oxidizer and fuel in solution.

This subject came up breifly about a month ago on arocket. There were several ways mentioned and I think it was call an "inverse hybrid". Google that and you will find many references.

The other idea that Monroe mentioned is a monopropellant, and that is another animal entirely. The common monopropellants are single chemicals like peroxide or hydrazine, but multiple chemical monopropellants have also been used such as sugar dissolved in peroxide.

I want to avoid mono propellants because of the hazards associated with them. I was thinking about a liquid fuel being injected onto a solid oxidizer grain. Not really looking for speculation but someone that has already "played with it".I'll check the "inverse hybrid" thing on ARocket.Rick

I'am not sure, there is a good reason to use an inverse hybrid. The Oxidizer takes the largest volume and getting it to vaporise and mix might be a sticking point . Pure nitromethane is a high performance (isp 300) monopropellant but it can detonate and that can ruin your day

Inverse Hybrid Rocket Project is a slideshow I found on google the good part about an inverse hybrid is using a dense oxidizer in this case they used ApSi Ap in a silicone? binder as an oxidizer really most inverse hybrids are a sort of oxygen rick solid fuel into which is injected a liquid fuel.